5.0 Biological Description of Sifton ESA

Botanists, zoologists, wildlife biologists and naturalists like to explore special areas that may support wildlife species not commonly found in the area. Examples of such species are orchids and carnivorous plants. Over time, the uniqueness of Sifton Bog has attracted its share of explorers, who documented in various formats aspects of the ecology of the bog ecosystem. Table 5 is a record of published studies on the flora of the Sifton Bog, including species accounts, post-graduate theses, life science inventories and evaluations for relative significance. By the 1950s the bog was officially protected in municipal policy (London Township) and recognized for its significant features (International Biological Programme site, Provincially Significant , Life Science Area of Natural and Scientific Interest, Significant Natural Area - now Environmentally Significant Area). When the first subdivision on the western side of the bog (Sifton Oakridge) was completed, the approval came with a conveyance of the most significant and unique section of the bog land to the UTRCA to be protected as a public open space.

In a proactive approach, the City, UTRCA, private sector landowners and community stakeholders undertook an Integrated Resource Management Study to provide context for future development around the bog and adjacent lands. D. McLeod (1992) completed the comprehensive life science inventory for the biological component of the study. This study was used as the baseline for several Environmental Impact Studies (EISs) that were completed in the mid-1990s (Table 5). The next quantitative study of the vegetation of the Sifton Bog was completed over the period 1998 - 2000 by a team of botanists subcontracted to BioLogic. This group coordinated the development of a monitoring program and set environmental targets to be implemented prior to development of the Crich/Drewlo lands along the eastern edge of the bog, by order of the Ontario Municipal Board. Thirteen permanent plots were established in the major vegetation communities on the bog mound and in the . These same plots were located and monitored in 2008 by B. Bergsma and Bradwill Ecological Consulting in order to detect shifts of species or changes to community associations.

In an effort to interpret this wealth of information related to communities and species over time, B. Bergsma and W. DeYoung summarized 11 species accounts by author, species, and species presence by vegetation association. The integrated species list is presented in Appendix D.

Appendix E summarizes the major vegetation associations as described by the various authors. Rather than simply converting each author’s community descriptions to the most recent Ecological Land Classification (ELC) for Southern Ontario (Leeet al. 1998), each community has been labeled according to the best descriptors, including Ontario Wetland Evaluation System community codes (OMNR 1993, as amended). This allows comparisons of species within communities over time. The final community classification has been converted to the most appropriate ELC equivalent.

27 Table 5. Botanical Studies of Sifton Bog Author Year Title (full references are in the bibliography) Dearness, Dr. John 1890 The Cyperaceae (Sedges) of Middlesex County. The Orchidaceae (Orchids) of Middlesex County. Crawford, Margaret 1926 Studies on the Byron Bog with special reference to Chamaedaphne calyculata (Leatherleaf). M.A. thesis. UWO. Judd, W.W. 1957 Studies of the Byron Bog in southwestern Ontario. I. Description of the bog. Judd, W.W. 1966 Studies of the Byron Bog in southwestern Ontario. XXVI. Distribution of shrubs and vines. Judd, W.W. 1967 Studies of the Byron Bog in southwestern Ontario. XXVIII. Distribution of club-mosses and ferns. Judd, W.W. 1969 Studies of the Byron Bog in southwestern Ontario. XL. Distribution of Sphagnum mosses. Orloci, Laszlo 1970 Analysis of Vegetation Samples Based on the Use of Information. Cook, Frank 1971 The distribution of mosses in the Byron Bog, Southwestern Ontario. Waldron, Gerry 1972 International Biological Programme (IBP) Checklist of vegetation and species. Small et al. 1977 The Significant Sensitive Areas of Middlesex County. Ontario Ministry of Natural Resources. Life Science ANSI programme. Proctor and Redfern 1979 Environmental Appraisal of proposed development property adjacent to Sifton Bog. Graham, R. 1987 Unpublished thesis; field sampling scheme and vegetation data from 90 quadrats at the Sifton Bog. Wu, Qiang 1989 Quantitative Analyses on the Vegetation of Byron Bog. M.Sc. thesis. UWO. McLeod et al. 1989 Wetland Data Record and Evaluation – Sifton Botanical Bog. McLeod, D. 1992 Integrated Resource Management Study: Life Science Inventory. Gartner Lee Limited 1993 Environmental Impact Study, Crich/Drewlo Property, Sifton Bog, London, Appendix F: Vegetation Community Descriptions prepared by B. Bergsma. Gartner Lee Limited 1995 Environmental Impact Study, Norquay Property, Sifton Bog, prepared by B. Bergsma. Waldron, G. 1999 - Pre-development monitoring of 13 geo-referenced 10 m x 10 m vegetation plots in the Sifton Bog B. Larsen 2000 (two seasons of data collection) including Sphagnum mosses. Submitted by BioLogic. S. Aboud J. Gerrath H. Kleb Bergsma, B. 2006 Life Science Inventory and Vegetation Community mapping update. Luckman, B. et al. 2007 Dendrochronology of Black Spruce and Tamarack at the Sifton Bog. Quinlan, C. 2006 - Reconnaissance-level and targeted site visits to specific communities to map species presence/ B. Gallagher 2007 absence, changes, threats, age (Appendix B). Bergsma, B. 2008 Post-development monitoring of 13 geo-referenced 10 x 10 m vegetation plots in the Sifton Bog. W. DeYoung In preparation by Bradwill Ecological Consulting. A. Bake M. Wolosinecky N. McKernan M. Kornoibis L. Kemp

28 5.1 Vegetation Community Mapping Early vegetation community maps that accompanied the botanical inventories listed above were simple inventories of species observed (Judd 1957; Waldron 1972). The first quantitative vegetation analysis was undertaken in 1987 - 1989 by UWO graduate students and their advisors, R. Jancey and L. Orloci. Since this information has not been documented in any other reports on the Sifton Bog, a summary of key findings and mapping are provided in this master plan. As English names are used throughout this plan, an English to Latin table is provided in Table 6.

McLeod (1992) prepared a detailed vegetation community map for the site (Map 10a). A second quantitative vegetation analysis was undertaken in 1998 - 2000 by BioLogic (2001) as a requirement for pre-development monitoring. In 2006 - 2007 vegetation communities were revisited for this master plan and the boundary and community types were adjusted based on the Ontario Wetland Evaluation System and ELC standards. The 2007 vegetation communities are represented on Map 10b.

The wetland area of the bog is approximately 23 ha in size. This bog area is composed of four major zones that are arranged in concentric rings beginning with the central : • Zone 1 - Redmond’s Pond, • Zone 2 - open sedge, shrub and treed bog communities, • Zone 3 - coniferous, mixed, deciduous and buckthorn swamps, and • Zone 4 - zone.

Various terrestrial communities surround the bog and provide buffer and related wildlife functions. These zones are consistent with the zones that Dr. Judd applied to the bog -- pond, floating bog, low woods and wooded slopes (Appendix M1).

Sixteen distinctive vegetation communities have been recognized and described by various authors over the last 80-year period. These vegetation communities have been divided into major systems and zones as shown in Table 7 and described in the following section. Figure 11 shows the boundaries of the ELC community Ecosites within Zones 1 to 3.

Vegetation communities are ranked for their rarity by the Natural Heritage Information Centre (NHIC) of the Ontario Ministry of Natural Resources. Most bog types are ranked as common in Southern Ontario; however, the leatherleaf shrub peatland of Sifton Bog is ranked S3 (rare to uncommon).

29 Table 6. Plant Names, English to Latin Common Name Latin Name Common Name Latin Name alders Alnus spp. Norway Maple Acer platanoides* Alternate-leaved dogwood Cornus alternifolia Pale Laurel Kalmia polifolia apple species Malus sylvestris or pumila Pitcher Plant (Northern) Sarracenia purpurea ash species Fraxinus spp. plantain species Plantago spp.* Big Bluestem Andropogon gerardii Red Maple Bitternut Hickory Carya cordiformis Red Oak Quercus rubra Black Ash Fraxinus nigra Red Osier Dogwood Cornus stolonifera Black Cherry Prunus serotina Robust Sedge lacustris Black Huckleberry Gaylussacia baccata Rose Pogonia Pogonia ophioglossoides Black Spruce Rough Cotton-grass Eriophorum tennelum Black Walnut Juglans nigra Round-leaved Sundew Drosera rotundifolia Bog Laurel (Pale Laurel) Kalmia polifolia Royal Fern Osmunda regalis Buttonbush Cephalanthus occidentalis rush Scirpus spp. cattails Typha spp. sedges Carex spp. Clearweed Pilea pumila Sensitive Fern Onoclea sensibilis Common Bladderwort Utricularia vulgaris Silky or Glossy Dogwood Cornus ammomum Common Buckthorn Rhamnus cathartica* Silver Maple Acer saccharinum Common Smartweed Polygonum hydropiper Small Cranberry Vaccinium oxycoccos Cottongrass Bulrush Scirpus cyperinus Soft Rush Juncus effusus dogwoods Cornus spp. Southern Pond Lily Nuphar advena (Nymphaea advena) duckweed Lemna spp. Sphagnum mosses Sphagnum spp. Eastern Redcedar Juniperus virginiana Sugar Maple Acer saccharum Eastern White Pine sundews Drosera spp. Fowl Manna-grass Glyceria striata Milkweed Asclepias incarnata Fowl Bluegrass Poa palustris Swamp Pink Arethusa bulbosa Freeman Maple (hybrid soft maple) Acer freemanii Swamp Rose Rosa palustris Glossy Buckthorn Rhamnus frangula* Swamp Thistle Cirsium muticum Grass Pink Calopogon tuberosus Tamarack Gray Dogwood Cornus racemosa Tartarian Honeysuckle* Lonicera tatarica Hackberry Celtis occidentalis Tawny Cottongrass Eriophorum virginicum hawthorns Crataegus spp. Three-way Sedge Dulichium arundinaceum Highbush Blueberry Vaccinium corymbosum viburnums Viburnum spp. Highbush Cranberry Viburnum trilobum Viper’s Bugloss Echium vulgare* Hop-hornbeam Ostrya virginiana Water Parsnip Sium suave Horned Bladderwort Utricularia cornuta Water Shield Brasenia schreberi Labrador Tea Ledum groenlandicum White Ash Fraxinus americana Large Cranberry Vaccinium macrocarpon White Beakrush Rhynchospora alba Largetooth Aspen Populus grandidentata White Birch Betula papyrifera Leatherleaf Chamaedaphne calyculata White Cedar (Eastern) Thuja occidentalis Little Bluestem Schizachyrium scoparium White Elm Ulmus americana Manitoba Maple Acer negundo* White Mulberry Morus alba* Fern Thelypterus palustris White Oak Quercus alba Marsh St. Johnswort Hypericum virginicum willow Salix spp. Mountain Maple Acer spicatum Winterberry Ilex verticillata Nannyberry, Sweet Viburnum Viburnum lentago Yellow Birch Betula alleghaniensis Northern Pitcher Plant Sarracenia purpurea Yellow Pond Lily Nuphar variegatum * Non-native

30 Legend (Ecological Land Classification Ecosites) SAF1 Floating-leaved Shallow Aquatic MAS3 Organic Shallow Marsh FEO1 Open BOO1 Open Bog BOS2 Shrub Kettle Bog BOT2 Treed Kettle Bog SWC4 Tamarack-Black Spruce Organic Coniferous Swamp SWM5 Maple Organic Mixed Swamp SWD6 Maple Organic Deciduous Swamp SWT3 Organic Thicket Swamp SWD3 Maple Mineral Deciduous Swamp (not shown here; see Map 10b)

Figure 11. Vegetation communities for Zones 1 – 3 of Sifton Bog, 2007

31 Table 7. Vegetation Zones and Community Descriptions for Sifton Bog ESA, 2007 Dominant Species Ecological Land McLeod Vegetation Community Location (based on OWES) Classification Ecosite 1992* WETLAND SYSTEM Zone 1: Redmond’s Pond [Pond – Judd] Open water floating-leaved Brasenia-Utricularia Redmond’s Pond SAF1: Floating-leaved Shallow 1a shallow aquatic Aquatic Southern Pond Lily organic Nymphaea-Typha Pond margins, pools, MAS3: Organic Shallow Marsh 1b shallow marsh ditches, water tracks Open floating Sphagnum- Rhynchospora-Sphagnum- 3 small bog south FEO1: Open Fen 1c sedge zone Drosera-Dulichium of Redmond’s Pond Zone 2: Open Bog [Floating Bog – Judd] Open Beakrush-Cotton Rhynchospora- Mat north of Redmond’s BOO1: Open Bog Graminoid 2a Grass graminoid-spruce Eriophorum-Drosera- Pond bog Dulichium Open Sphagnum-heath Chamaedaphne- Mat east and west of BOS2: Shrub Kettle Bog 2b bog Vaccinium-Eriophorum Redmond’s Pond, and south of boardwalk Open spruce-Tamarack- Larix-Picea-Sphagnum- Mat east of pond, north of BOT2: Treed Kettle Bog 2c Sphagnum and heath treed Chamaedaphne- boardwalk bog Vaccinium-Sarracenia- Eriophorum Zone 3: Swamps [Low Woods – Judd] Closed spruce-Tamarack Picea-Larix-Vaccinium- Outer edge of bog mat SWC4: Tamarack-Black Spruce 3a swamp forest Sphagnum Organic Coniferous Swamp Closed organic mixed Pinus-Larix-Acer rubrum- Outer border of low damp SWM5: Maple Organic Mixed 3b swamp Betula woods Swamp Closed organic deciduous Acer rubrum-Betula- Low woods SWD6: Maple Organic 3c swamp Rhamnus frangula Deciduous Swamp Closed mineral maple Acer freemanii Swamp in the southwest SWD3: Maple Mineral 1b swamp corner Decidous Swamp Tall shrub organic swamp Rhamnus-Salix From bog margin to lagg SWT3: Organic Thicket Swamp 3d thicket zone Zone 4 – Lagg Zone Organic graminoid Carex-Scirpus-Juncus- Lagg zone by start of MAM3: Organic Meadow 2b meadow marsh Glyceria boardwalk Marsh TERRESTRIAL SYSTEM [Wooded Slopes – Judd] Closed oak-cherry-maple Quercus-Prunus-Acer Upland slopes around bog FOD1: Dry-Fresh Oak 5 forest Deciduous Forest Closed Sugar Maple forest Acer saccharum Forest in the SW corner FOD5: Dry-Fresh Sugar Maple 5c Deciduous Forest Open hawthorn- Crataegus-Rhamnus- Eastern tableland CUW1: Mineral Cultural 6a buckthorn-honeysuckle- Lonicera-Populus Woodland poplar woods Meadow and young Acer saccharum-Crataegus- Open fields at the south CUM1: Mineral Cultural 6c woodland (maples, Viburnum-Poa end of the ESA Meadow hawthorn, Viburnum, grasses) Open Little Bluestem-Big Schizachyrium scoparium- Former gravel pit on slope TPS1: Dry Tallgrass Savannah 7 Bluestem prairie-savanna Andropogon gerardii east of bog and swamp * Map 10a shows McLeod’s vegetation communities. OWES = Ontario Wetland Evaluation System

32 5.1.1 Zone 1 - Redmond’s Pond Redmond’s Pond supports a floating-leaved, shallow, open-water, aquatic ecotype. Pond depth is variable, generally less than 2 metres. Water levels fluctuate with the amount of precipitation over a season, but in general depth of water has been decreasing over time while the size of the pond has remained fairly constant. The bottom of the pond is not solid, but consists of unconsolidated that becomes firmer with depth. At the deepest part of the kettle lake the peat layer extends approximately 10 m down before the sand and gravel aquifer is encountered. Key plants of the pond are Southern Pond Lily, with Water Shield, Common Bladderwort and cattail. Southern Pond Lily, which holds its leaves upright out of the water, is at the northern extent of its range limit and is considered “sensitive” in Ontario (NHIC website).

The extent to which Redmond’s Pond is covered by these aquatic plants varies from year to year. Distribution and abundance of the aquatic plants show some relationship to pond water level, with more coverage by pond lilies during shallower (drier) years. In the last couple of years the abundance of aquatic plants has shown decline, which may be due to an overpopulation of Goldfish, which have been illegally introduced in the pond. Goldfish are members of the minnow family and reproduce quickly and uproot and consume aquatic vegetation.

A few small pools to the south and slightly west of Redmond’s Pond have similar species composition, although they have more fen indicators. Redmond’s Pond with floating plants, 2000 5.1.2 Zone 2 - Open Bog There is no defined edge to Redmond’s Pond; rather, the edge is defined as a band ofSphagnum , sedges and sundews that floats on the water’s surface. The mat is made up of the plants themselves plus the roots and rhizomes (underground stems) of these and other plants, both dead and alive. This mat would not support the weight of a person or animal. Primary plants in this zone are Sphagnum, Small Cranberry, White Beakrush and Round-leaved Sundew. Sedges are the primary pioneer plants in bog succession.

As the mat becomes more consolidated with increasing distance from the open water, it is able to support more species of bog plants, particularly those in the Ericaceae family. Leatherleaf is the dominant low shrub in this zone. Tawny Cotton Grass, Large Cranberry, Three-way Sedge and a few (<10 % cover) scattered short or stunted Tamarack grow in the low-shrub zone. The three mosses that dominate the mat are Sphagnum fuscum, S. magellanicum, and S. fimbriatum. When in flower in early summer, Bog Laurel and orchids such as Grass Pink and Rose Pogonia add colour to the mat.

The outer ring of the bog is similar to the low shrub zone; however, the presence of 10 - 25% cover of stunted Black Spruce and Tamarack qualifies this zone as a treed bog. One may also find Pitcher Plants, orchids, and some taller shrubs such as Highbush Blueberry and Black Huckleberry.

33 5.1.3 Zone 3 - Swamps A series of swamps (treed ) surround the bog communities. A very narrow coniferous band contains Black Spruce and Tamarack trees that are greater than 2 - 5 metres in height and have a canopy closure of more than 60% cover. This community is a defining limit of the bog mound and represents the final stage of bog succession. Sedges,Sphagnum mosses of different species, low and tall shrubs, as well as other shade-tolerant mosses and ferns, occur here. The peat underneath this vegetation type is only a few metres deep and more consolidated than peat closer to the centre of the bog, thus providing greater stability for trees.

The rest of the wetland is composed of mixed, deciduous and thicket swamps. These swamps are underlain by organic soil, not deep layers of peat as in the bog. The mixed deciduous and coniferous swamp is transitional between the coniferous swamp and deciduous swamp. Here, Black Spruce is replaced by Tamarack. White Birch, Eastern White Pine, Silver Maple and Freeman Maple (a hybrid between Silver and Red Maple) occupy the canopy layer. These swamps are wet most of the year, except in dry summers. There is a shallow man- made pond within the swamp at the end of Naomee Place. The original owner of the greenhouses on Riverside Drive owned this strip of land and hand-dug the pond (locally known as Turtle An old well casing in the swamp near Naomee Place, is evidence of past digging to Pond) to provide water for the create a pond to supply water for the greenhouses on Riverside Drive. greenhouses. Water was pumped out of the swamp from at least 1950 to the mid 1990s.

The organic deciduous swamps are dominated by Freeman Maple with some White Birch and only the occasional Eastern White Pine. The understorey is almost entirely Glossy Buckthorn. In the past, other shrubs were present, including Swamp Rose, Winterberry, Mountain Maple and Red Osier Dogwood (McLeod 1992), but there is little evidence of them today. Several fern species have been recorded including Sensitive, Royal and Marsh Fern.

Large areas to the north, west and south of the bog communities, previously classified as mixed and deciduous swamps, are now occupied by a Glossy Buckthorn thicket swamp. Thickets are wetlands dominated by tall shrubs, not trees. The thicket is a virtual monoculture of buckthorn. The trees and shrubs cannot regenerate in the dark understorey of the buckthorn; nor can they withstand the heavy deer browse. It is expected this zone will become a buckthorn thicket in the future if no intervention is carried out. Some dead or dying trees still peek out of the overstorey, but these trees are not regenerating. The origin of the buckthorn appears to be from the northeast corner of the bog, where it was harvested up until 1945.

5.1.4 Zone 4 - Lagg Zone The outer margins of the bog are occupied by various wet and swamps that contain standing water throughout most of the season. A small emergent meadow marsh community occurs north of the deciduous swamp near the Oxford Street entrance. This community is dominated by emergent herbaceous plants with a scattering of Silver Maple. Species in this

34 marsh-like area include Robust Sedge, Soft Rush, Common Smartweed, Cottongrass Bulrush, Swamp Milkweed, and Fowl Manna-grass. Other plants include Clearweed, Water Parsnip, and Swamp Thistle.

At the toe of the eastern slope in the lagg zone is a vegetation community that includes Manitoba Maple, willow, and Hackberry trees. Also present are Buttonbush, sedges, and Sensitive Fern.

At the southwest end of the ESA, the lagg zone is represented by a series of small deciduous swamps, Silver Maple Swamp west of Havenwood, Spring 2006 located roughly between Havenwood Way and Naomee Place. These shallow depressions (dug by hand some years back to produce water for greenhouses) usually have standing water for most of the spring and summer. The swamps are dominated by Silver/Red Maple, willows, Gray Dogwood, Red Osier Dogwood and Clearweed. A mat of floating duckweed often covers the standing water in summer.

The swampy area along the western edge of the ESA is underlain by mineral soil that has only a thin layer of organic soil on top. This area is very small, drier than the other swamps, and is dominated by a few large willow trees.

5.1.5 Deciduous Forests There are both young and mature forests within the ESA. Despite age differences, all of the forest communities have low species diversity in the ground and shrub layers. This is hypothesized to be due to the heavy pressure of deer browse.

The forests in Naomee Park (southwest corner of the ESA) are mature and dominated by Sugar Maple, which occupy 60% of the overstory. A Sugar Maple and Black Cherry forest (FOD5) occurs on the flatter, moister ground. The tree species assemblage is interrupted by Silver Maple swamps (SWD3) that include other tree species tolerant of wetter conditions including Black Walnut, White Elm and Hackberry.

The large forested area in the southeast part of the ESA, west of Old Hyde Park Road, is a young forest (CUW1). Historically, this area was cleared for agriculture, but it has naturalized since about 1940 (Maps 7a, 7b). The resulting forest contains a wide variety of tree and shrub species representing both early and mid-successional forest development stages. Sugar, Silver, Norway and Manitoba Maple are all present. There are small, sunny openings dominated by hawthorns, viburnums such as Nannyberry and High-bush Cranberry. Non-native grasses form the groundcover. Low spots support Silver Maple and Gray Dogwood. A few large Bitternut Hickory and Eastern White Pine are present. Throughout, non-natives such as Common Buckthorn and Tartarian Honeysuckle are mixed with the native species.

On the north-facing slopes at the south end of the ESA is a mature forest dominated by White and Red Oak (FOD1). A wide range of other trees is present, including Sugar Maple, Black

35 Cherry, White Ash, Bitternut Hickory and Hop-hornbeam. The trees in this community are large and stately, but there is little regeneration, likely due to heavy browsing by deer. Common Buckthorn, a non-native shrub, is one of the few species present in the shrub layer.

5.1.6 Savanna and Shrub Thickets A unique savanna habitat has taken over the former gravel pit on the eastern side of the bog (TPS1). Tallgrass prairie grasses including Big Bluestem and Little Bluestem have colonized the loose, sandy soils. A scattering of native and non-native trees has become established here. Mid-sized Bitternut Hickory, ash, Eastern Redcedar, Eastern White Pine, Largetooth Aspen and many dead White Elm trees are present. Clusters of non-native shrubs are also present including White Mulberry and Tartarian Honeysuckle. The groundlayer contains many non-natives including Vipers’s Bugloss, plantain and non-native grasses. There is a lot of disturbance from bicycles and bonfires in this area (currently private property).

A woodland community, defined as a treed community having 35 - 60% cover, is present along the eastern slopes and tableland of the bog. The area immediately south of Oxford Street was under cultivation in 1945, but was left to naturalize in the early 1950s. Remnants of a former apple orchard are notable because of the presence of some apple trees and many species of hawthorn (CUW1). This community, which functions as a buffer for the bog, is being taken over by Common Buckthorn. The buckthorn grows to a height of 4 m and forms a closed canopy. As a result, there are few other plants. Alternate-leaved, Silky and Gray Dogwoods are found in small numbers in the more moist areas.

5.2 Vegetation Patterns The total of 518 species have been identified from Sifton Bog ESA over the years, as follows: • Tree - 57 species • Shrub - 87 • Vine - 15 • Forb - 232 • Fern, fern ally - 18 • Graminoid - 97 • - 12 Little Bluestem covers the loose sandy soil in the old Of these species, 133 or 26% are non-native or introduced, gravel pit. reflecting typical urban natural areas. Based upon the 11 species inventories that have been assembled (Appendix D), 38 species have been identified by six or more different authors (Appendix F1). Fourteen of these species occur on the list of 17 unique plant descriptors used in the quantitative analysis of the Sifton Bog vegetation by Wu (1989). Missing are Sphagnum recurvum (Sphagnum will be discussed in another section), Fowl Bluegrass and Rough Cotton-grass. The 14 common descriptor species are listed below. 1. Red Maple 8. Large Cranberry 2. Tamarack 9. Small Cranberry 3. Black Spruce 10. Round-leaved Sundew 4. Leatherleaf 11. Pitcher Plant 5. Pale Laurel 12. Sensitive Fern 6. Glossy Buckthorn 13. Tawny Cottongrass 7. Highbush Blueberry 14. Common Cattail

36 5.2.1 Quantitative Vegetation Grouping Wu (1989) used an iterative ranking and clustering analysis method to identify vegetation patterns of the open bog and swamp zones. The analysis recognized four major vegetation groups, of which there were two bog (A and B) and two woodland (C and D) groups. The discriminating descriptors to separate the vegetation groups, the important descriptors in each vegetation group, and the distribution of the vegetation groups in the bog were described by Wu (1989).

Glossy Buckthorn and Black Spruce, as well as pH and nitrate, were distinctive species and environmental factors distinguishing open bog from woodland. In the A bog grouping, Tamarack in the tree level, Small Cranberry in the shrub level, and Round-leaved Sundew and Pitcher Plant in the herb level were the primary vegetation descriptors, while nitrate was the environmental factor that distinguished bog vegetation. In the open bog, additional nitrogen is provided by insectivorous plants that digest proteins of trapped animals. The presence of Tamarack, Large Cranberry, Sensitive Fern, and Common Cattail, and the pH distinguish the bog pond and pond margin area (Group B) from the open shrub bog area.

In the woodland groupings, there is a southern woodland association (Group C) and a northern woodland association (Group D). Key descriptors for these two groups were: Black Spruce – Pale Laurel – Fowl Bluegrass in the southern woodland of the bog, and Red Maple – Glossy Buckthorn – Highbush Pitcher Plant and Round-leaved Sundew in Sphagnum Blueberry in the northern woodland.

5.2.2 Black Spruce and Tamarack Colonization of Bog Mat Luckman (2007 in preparation) looked at the colonization patterns, growth, and relationship to disturbance of Tamarack and Black Spruce at the Sifton Bog by means of tree ring analysis, referred to as dendrochronology. In total, 113 Tamarack and 44 Black Spruce were sampled. Chronologies were developed from the samples. The oldest Tamarack was 129 years, while the oldest spruce was only 79 years. This reflects the time when spruce trees were harvested during the war and for Christmas trees. The oldest trees occur primarily to the east of Redmond’s Pond, but are distributed throughout the bog mat. Luckman noted that over the last 25 years, colonization has occurred between existing trees to increase the density, rather than advancing into the open bog area. There were good relationships between historical events and the tree ring analysis; for instance, the burning of the bog in 1886 and cutting of Christmas trees in the 1940s limited the number of trees that colonized the bog. The oldest trees are located in the coniferous and mixed swamps of zone 3.

5.2.3 Basal Area Analysis In 2007, three woodland communities were evaluated for basal area: Stand 1 (FOD5), Stand 2 (FOD5-7), and Stand 3 (FOD1). Stands 1 and 2 are young to mid-age woodlands; Stand 3 is a mid-age to mature woodland. Map 8 shows the plot locations.

The analysis showed that there is a dense stand of medium, large and extra large trees, a rarity in southern Ontario. However, about 30% of the trees were declining or dying, and there was a lack of saplings, likely due to heavy shade and deer browse pressure. This analysis is discussed in more detail in Section 7.8.

37 5.3 Rare, Conservative and Unusual Plants of the Sifton Bog 5.3.1 Rare Plants The dominant species that make up the bog mat have remained present for many decades. Most of the bog plants are considered regionally rare, that is, rare in Middlesex County, and a few are provincially rare. McLeod (1992) noted five provincially rare plants: three bog and two terrestrial species (Table 8).

Table 8. Provincially Rare Species Listed in McLeod 1992 and their Status Today General 2007 Provincial Latin Name Common Name Last Verified Notes* Location Status* Carex atlantica ssp. Atlantic Sedge Treed Bog 1992 (McLeod) S1, Only known from a few capillacea May be at Risk in eastern Ontario. Crataegus dodgei var. Dodge’s Hawthorn Upland Thicket 1992 (McLeod) S4, Confined to extreme dodgei Secure southern Ontario. Nuphar advenum (Now N. Southern Pond Lily Redmond’s 2007 S3, Confined to extreme advena) Pond (UTRCA) Sensitive southern Ontario. Panax quinquefolius American Ginseng Upland woods 1894 S2, Probably extirpated Endangered from ESA and area. Scirpus smithii or Smith’s Club-rush Pond edge 1992 (McLeod) S2?, Southern species. Schoenoplectus smithii May be at Risk *Status and Notes taken from the Natural Heritage Information Centre (NHIC) website.

5.3.2 Highly Specialized (Conservative) Plants The coefficient of conservatism (CC) is a value assigned to individual native plant species that represents their degree of tolerance to disturbance and fidelity to specific . Plants with a coefficient of conservatism from 8 to 10 will occur in highly specialized habitats, with a narrow ecological niche. Species with a low CC (0 - 3) may occur in a wide variety of habitats, including disturbed sites. At Sifton Bog, 64% of the flora are specialized to an ecological niche (Table 9a). Another 18% of the flora are highly specialized, with a high CC (8 - 10). The habitat of the bog mound at Sifton Bog is highly specialized and supports plants with a narrower ecological niche, including 26 plant species with a CC of 10 (Table 9b).

Table 9a. Summary of Coefficients of Conservatism of Sifton Bog Plants Number of Percent of Fidelity of CC Percent Species Total species Habitat 10 26 7.2 Highly 9 13 3.6 17.7 Specialized 8 25 6.9 7 46 12.7 6 60 16.6 Specialized 64.0 5 61 16.9 4 64 17.7 3 37 10.2 2 20 5.5 Common 18.3 1 9 2.5 361 100.0 100.0

38 Table 9b. Species Found in Sifton Bog with a Coefficient of Conservatism 8 - 10 Latin Name Common Name True Bog* CC=10 Andromeda polifolia ssp. glaucophylla Bog Rosemary + Arethusa bulbosa Swamp-pink Carex atlantica ssp. capillacea Eastern Sedge + Carex chordorrhiza Creeping Sedge Carex limosa Mud Sedge Carex magellanica ssp. irrigua Bog Sedge Carex oligosperma Few-seeded Sedge + Carex pauciflora Few-flowered Sedge + Carex tenuiflora Sparse-flowered Sedge Eriophorum gracile Slender Cotton Grass + Eriophorum virginicum Tawny Cotton Grass + Kalmia polifolia Pale Laurel Maianthemum trifolium Three-leaf Solomon’s-seal Pogonia ophioglossoides Rose Pogonia Quercus prinoides Dwarf Chinquapin Oak Rhynchospora alba White Beakrush + Salix pyrifolia Balsam Willow Sarracenia purpurea Northern Pitcher Plant + Scirpus smithii Smith’s Club-rush Selaginella selaginoides Low Spike-moss Silene virginica var. virginica Fire-pink Triadenum virginiucm Marsh St. John’s-wort Vaccinium macrocarpon Large Cranberry + Vaccinium oxycoccos Small Cranberry + Woodwardia virginica Virginia Chainfern Zigadenus elegans ssp. glaucus White Camass CC=9 Calopogon tuberosus Tuberous Grass-pink Carex trisperma var. trisperma Three-fruited Sedge Carex trisperma var. billingsii Three-fruited Sedge Carya glabra Pignut Hickory Chamaedaphne calyculata Leatherleaf + Drosera intermedia Spoon-leaved Sundew + Ledum groenlandicum Labrador Tea + Lycopodium inundatum Northern Club-moss Menyanthes trifoliate Bog Buckbean + Panax quinquefolius American Ginseng Quercus muhlenbergii Chinquapin Oak Taenidia integerrima Yellow Pimpernel Utricularia cornuta Horned Bladderwort

39 Table 9b (continued)

Latin Name Common Name True Bog* CC=8 Asclepias exaltata Poke Milkweed Asclepias tuberosa Butterfly Milkweed Carex disperma Soft-leaved Sedge Carex lasiocarpa Slender Sedge Carex leptalea ssp. leptalea Slender Sedge Celtis occidentalis Hackberry Cercis canadensis Redbud Cirsium muticum Swamp Thistle Coeloglossum viride var. virescens Bracted Green Orchid Eleocharis olivacea Bright-green Spike-rush Eleocharis ovata Ovate Spike-rush Galium brevipes Limestone Swamp Bedstraw Galium lanceolatum Torrey’s Wild Licorice Galyussacia baccata Black Huckleberry Goodyera pubescens Downy Rattlesnake-plantain Juncus pelocarpus Brown-fruited Rush Lonicera oblongifolia Swamp Fly Honeysuckle Nemopanthus mucronatus Mountain Holly Picea mariana Black Spruce + Pinus resinosa Red Pine Platanthera psycodes Small Purple-fringed Orchid Quercus bicolor Swamp White Oak Scirpus pedicellatus Stalked Bulrush Sorghastrum nutans Yellow Indian-grass Vaccinium corymbosum Highbush Blueberry Note: This list includes species documented in previous reports, especially McLeod 1992. Not all are confirmed to be present today. * True Bog = True Bog Species, in other words, species that grow only in bog environments.

5.3.3 Unusual Plants - Insectivorous Plants Of all the plants at the Sifton Bog, the most unusual are the insectivorous or carnivorous plants. By capturing prey insects as a source of nitrogen, these types of plants have adapted to living in an environment where nitrogen is not available. Three different species catch and trap insects in three different ways. The Horned Bladderwort captures its prey using underwater hollow leaves that bear an opening armed with trigger hairs. When an insect trips the hairs, the leaves expand and suck the insect inside. This type of trap is an active trap. There are two passive trap plants at the Sifton Bog. The Pitcher Plant is a pitfall trap. Insects crawl into the tubular- shaped leaves that are partially filled with water. The insects are unable to escape because of the stiff hairs along the inner wall of the leaf that point downward. Sundews are adhesive traps. They have a rosette of small leaves covered by thick glandular hairs that have a drop of highly viscous fluid at the ends. When an insect lands on the hairs it sticks as if to flypaper. The leaf encloses the insect, which is then digested by proteolytic enzymes (Larsen 1982).

5.3.4 Unusual Plants - Orchids Other specialized plants of botanical interest are the native orchids. They are not generally numerous in occurrence and many are threatened by disturbance and are quite rare to find. At Sifton Bog, 11 species of orchids have been observed (Table 10).

40 5.3.5 Unusual Plants - Ericaceae (Heath Plants) Many species of plants that are members of the family Ericaceae have morphological and physiological adaptations that allow them to colonize bog habitats. One of the most significant of these adaptations is the plants’ requirement for fungal root associations known as mycorrhizae. It is also known that many members of the Ericaceae family possess compounds (acetylandromedol) in their tissues that are toxic to animals and, therefore, such plants are seldomly grazed for very long. Most of the Ericaceae are low shrubs. They have fragrant flowers, often in great clusters, and glossy evergreen and hairy leaves. Interestingly, these leaf adaptations resemble those of xerophytic desert plants in that such ericaceous plants possess leaf structures that reduce water loss through evaporation and transpiration. These adaptations include thick, leathery leaves; a thick, shiny, waxy cuticle over leaf surfaces; and a thick mat of tomentum (hair) over the undersurface of the leaves where stomata are located. Some species, such as Labrador Tea, have revolute borders that curl around and partly cover the hairy underside of the leaves, like a windbreak (Larsen 1982).

The most common shrub in this family is Leatherleaf, also known as Cassandra. Crawford (1926) completed a study of the distribution and growth of Leatherleaf in the Sifton Bog to determine what environmental factors may contribute to the variations in growth as observed. She described the plants’ morphology: The leaves are nearly evergreen, coriaceous, waxy green above and scurfy white below. The flowers are white bells borne in the axils of the upper small leaves, forming small, one-sided leafy racemes. They bloom from the middle to end of June. It has rhizomes that intermingle and form the bog mat.

Leatherleaf

Her conclusions indicated that the variation in height, luxuriancy and yearly development of Leatherleaf is not only related to plant age, but also may be due to the varied concentrations of dissolved oxygen in the soil water.

Table 10 lists the unusual plants found in the past and notes about their current status. As many orchids have very short blooming periods and may not bloom every year, additional timed field work is needed to confirm their current presence or absence. Pitcher Plants were once fairly common on the bog mat and, in 2006, over 30 were seen in one summer day. However, in 2007 very few could be found and the cause is unclear (Dr. Nusha Keyghobadi, personal communication). There is anectodal evidence that deer are eating Pitcher Plant flowers and leaves.

41 Table 10. Unique and Unusual Plants Found in Sifton Bog and Last Recorded Date of Observation Date of Last Recorded Plant Found in 2006 - 2007 Observation Insectivorous Plants Pitcher Plant – Sarracenia purpurea More than 30 were found in 2006, but only a few in 2007. None could be found in the fall of 2007. Many babies found again in spring 2008. Round-leaved Sundew – Drosera rotundifolia Abundant (thousands) in 2007 Spatula-leaved Sundew – Drosera intermedia 1990 Horned Bladderwort – Utricularia cornuta One patch found on the mat in 2007 Orchids Grass Pink – Calopogon pulchellus Numerous (more than 50) in 2007 Rose Pogonia – Pogonia ophioglossoides Numerous (more than 50) in 2007 Dragon’s Mouth – Arethusa bulbosa 1990; previously more common Ragged Fringed Orchis – Habenaria lacera or 1991 Platanthera lacera Tall Northern Orchid – Platanthera hyperborea 1907 Small Purple-fringed Orchid – Platanthera psycodes 1890 - 1900 Nodding Ladies’ Tresses – Spiranthes cernua 1964 Ericaceous Plants Bog Rosemary – Andromeda polifolia 1990 Leatherleaf – Chamaedaphne calyculata Dominant plant in 2007 Wintergreen -- Gaultheria procumbens 1990 Black Huckleberry – Gaylussacia baccata Not abundant, but many shrubs found in 2007 Pale Laurel – Kalmia polifolia 6 plants in 2007 Labrador Tea – Ledum groenlandicum 1926; one plant Highbush Blueberry -- Vaccinium corymbosum Not abundant, but many shrubs found in 2007 Large Cranberry – Vaccinium macrocarpon Abundant 2007 Small Cranberry – Vaccinium oxycoccus Abundant 2007

5.3.6 Floral Regional Indicators Most of the bog plants that are considered regionally rare, that is, rare in Middlesex County with less than five locations occurring, are also considered to be boreal indicator species, common in northerly bogs but not in southern Ontario bogs.

Of the provincially significant species (Table 8) only Atlantic Sedge is a boreal bog species. There are 19 species present in the bog that are true bog species (Appendix F2). Thirty-six species are commonly found in habitats on the Canadian Shield (Appendix F2). Two species, Water Shield and Marsh St. John’s Wort, are considered to be Atlantic Coastal Plain Flora indicator species (Appendix F2). Four of the provincially significant species are considered southern or Carolinian species and are at-risk because they are at the northern extent of their ranges. Only one of the species in Table 8, Southern Pond Lily, was identified in 2006/07, but extensive field work was not undertaken to locate the other plants.

42 5.3.7 Sphagnum Sphagnum is an “ecosystem engineer” that is not simply adapted to wet, nutrient-poor and acidic conditions, but rather generates conditions unfavourable for other plants to gain a competitive advantage (Hebda et al. 2000). The Sphagnum family differs from other moss families by having a high water-holding capacity. A spongy leaf structure results from many large, perforated, water-absorbing, hyaline cells that are interwoven among live epithelial cells. Sphagnum can hold up to 20 times its dry weight of water.

Sphagnum moss is an important component of bog ecology. It readily soaks up water and creates an acidic environment for itself and other bog plants. It does this by the exchange of hydrogen ions for other cations (Ca+2, Mg2+, K+ and Na+). The acidity provided by Sphagnum gives direction to bog succession, with different species in control at each stage toward drier and more acidic conditions (Larsen 1982).

Judd undertook the first inventory of Sphagnum at the Sifton Bog in 1967. A second Sphagnum Moss inventory of Sphagnum was made in 1998 as part of the resource monitoring for the Sifton Bog by the developer’s consultant, BioLogic. The records from both studies are reproduced in Appendix G. Both authors found Sphagnum magellanicum present in the open bog and open shrub bog communities. The treed bog supported S. capillaceum, recorded by Judd and BioLogic. This same species was found also in the mixed swamp community, along with S. fimbriatum, S. recurvum, and S. magellanicum. The communities having the highest diversity of Sphagnum were the closed conifer swamp forest, with eight different species recorded; and the open fen, also with eight species.

5.4 Wildlife

5.4.1 Birds The Sifton Bog is an isolated “island” habitat not large enough to support a high diversity of wildlife. Even still, for a small area, the fauna is quite diverse, enhanced by the unique variety of plant life. McLeod (1992) confirmed 70 breeding bird species for the site out of an historic record of 124 bird species. Any decline in species diversity over time parallels the decline of many species across southern Ontario, largely due to habitat loss. In 1999 and 2000, through fixed point count monitoring and random surveys, BioLogic observed 47 different species of birds. A list of birds observed and the frequency of observation are included in Appendix H1.

In the spring and fall, many species of warblers, sparrows and other migrants can be found. In some winters, the Black Spruce and Tamarack cones attract winter finches such as Pine Grosbeak, White-winged Crossbill, Pine Siskin, and Purple Finch. Great Horned Owls have been known to hunt for small mammals such as mice, voles and rabbits in and around the bog. A Great Horned Owl was seen in the fall of 2007 during the deer count. In the spring, Mallards and Canada Geese stage or nest on the pond and in areas of standing water. Black- capped Chickadees are seen often in the bog and surrounding swamps.

43 5.4.2 Butterflies Many of the early animal records for the Sifton Bog are from Dr. W.W. Judd, who studied the insect life of the bog for many decades. In mid-summer, dragonflies and damselfies are common around the ponds. Many species of butterflies have been recorded including the rare Bog Copper, which, in its larval stage, feeds on the cranberry plant, and Brown Elfin, which, in its larval stage, feeds on the blueberry plant. These two butterflies were confirmed in 1992 by Dave McLeod. The Bog Copper was found in abundance in 2007 by local butterfly enthusiast Allen Dlugan (Ovanin 2007). He noted little luck finding it in previous years.

5.4.3 Amphibians and Reptiles The wet conditions at the bog attract a range of amphibians and turtles. In the past, seven species of Bog Copper (Photo: Rosemary Scott) amphibians have been recorded in Sifton Bog. These were Tetraploid Gray Treefrog, Spring Peeper, Green Frog, Wood Frog, Chorus Frog, Leopard Frog and American Toad. The Gray Treefrog, Spring Peeper and Green Frog were confirmed in 2007 through evening surveys. An inventory of wildlife was updated by Dave Martin in 1999 as part of the pre-development biological monitoring program (BioLogic 2001). They confirmed the breeding of Grey Treefrog, Spring Peeper, Green Frog, Wood Frog and American Toad.

Painted Turtles and sometimes Snapping Turtles are seen basking on logs in the pond. Spotted Turtles were recorded historically in the site, but have not been seen for many years and are probably extirpated from the area. A Blanding’s Turtle was recorded in the past, but may have been released from another habitat.

5.4.4 Mammals A large population of White-tailed Deer resides in the ESA. These herbivores eat a wide variety of plants but favour deciduous trees, cedars, shrubs and herbaceous plants. Deer were not commonly seen in the bog in the 1960s and 1970s (London Public Utilities Commission circa 1980). Over time, the population has increased as development has proceeded to change agricultural fields and meadows to residential development.

Other mammals common to urban environments include Red Fox, Cottontail Rabbit, Raccoon, Striped Skunk and Gray Squirrel. There are historical records of European Hare, Masked Shrew, Smoky Shrew and Southern Bog Lemming, none of which has been seen for decades. A dead Meadow Vole was seen hanging from a branch in the mixed swamp along the boardwalk in 2006, likely cached by a Northern Shrike or other raptor.

Incidental observations were made in 2006 - 2007 and are listed in Appendix H2.

44